A scroll-type compressor described in Japanese Unexamined Patent Publications (Kokai) Nos. 3-33486 and 58-101287 as a variable capacity-type compressor comprises a bypass hole formed at the end plate of a fixed scroll for establishing the communication between the compressor working chamber and the suction side, wherein by opening and closing the bypass hole, the discharge capacity of the compressor is variable. For opening and closing the bypass hole, a solenoid valve or valve means utilizing the differential pressure between the suction pressure and the discharge pressure is used.
The means described above, however, increases the number of parts constituting the variable capacity-type compressor and complicates the structure thereof. The problem is posed, therefore, that the manufacturing cost of the variable capacity-type compressor may be increased and the reliability (durability) thereof may be reduced.